A comprehensive explanation of the functions and performance of the vro Test

I learned about the performance of a vro, So I studied the basic steps and special attention of the vro test. I would like to share it with you here and hope it will be useful to you. Vro testing can be divided into the following categories: Function Testing, performance testing, stability and reliability testing, consistency testing, interoperability testing, and network management testing.

(1) Functional Testing

Router functions can be divided into the following aspects.

(1) interface function: This function is used to connect a router to a network. It can be divided into two types: LAN interface and WAN interface. LAN interfaces mainly include Ethernet, card ring, Token Bus, FDDI and other network interfaces. Wan interfaces mainly include E1/T1, E3/T3, DS3, and general serial port (can be converted to X.21DTE/DCE, V.35DTE/DCE, RS232DTE/DCE, RS449DTE/DCE, EIA530DTE) and other network interfaces.

(2) Communication Protocol function: This function is responsible for handling communication protocols, including TCP/IP, PPP, X.25, frame relay, and other protocols.

(3) data packet forwarding function: This function is mainly responsible for forwarding data packets between ports (including logical ports) based on the content of the route table and rewriting the data packet header information at the link layer.

(4) routing information maintenance function: This function runs the routing protocol and maintains the route table. The routing protocols include RIP, OSPF, and BGP.

(5) Management Control Function: vro test management control function includes five functions: SNMP proxy function, Telnet server function, local management, remote monitoring and RMON function. Control and Manage vrouters in multiple ways and allow logging.

(6) security function: Used to complete data packet filtering, address conversion, access control, data encryption, firewall, address allocation, and other functions. The router does not need to fully implement the above functions. However, because a vro acts as a network device and has a minimum function set, the vro test must support the functions specified by the minimum function set. Because the vast majority of functional tests can be covered by interface testing, performance testing, protocol consistency testing, and network management testing, vro testing generally only performs validation tests on functions that cannot be covered by other tests. Vro testing generally adopts the remote test method.

(2) Performance Testing

A router is the core device of an IP network. Its performance directly affects the scale, stability, and scalability of the IP network. Because the IETF does not have specific provisions on the router performance test, generally only RFC2544 (Benchmarking Methodology for Network Interconnect Devices) can be used for testing. However, a router is different from a simple network interconnection device. In performance testing, a router-specific performance test should also be added. Such as the capacity of the route table and the convergence time of the routing protocol. The router performance test should include the following indicators.

(1) throughput: test the router packet forwarding capability. Generally, it refers to the limit of packet forwarding per second on a vro without packet loss. Generally, you can use the binary method to find this threshold.

(2) latency: The interval between the time the router receives the packet and forwards the packet within the throughput range. The latency test should be repeated 20 times and then the average value is obtained.

(3) packet loss rate: test the proportion of dropped packets on the vro under different loads to received packets. Different loads usually refer to the test from throughput to line speed (the highest rate of transmission packets on the Line). The step size generally uses 10% of the line speed.

(4) Number of back-to-back frames: the maximum number of packets that can be processed by the router when the packet is transmitted at the minimum packet interval without packet loss. This test actually tests the router cache capability. If the router has the line rate capability (throughput = interface media line rate), this test is meaningless.

(5) system recovery time: the time when the test router resumes normal operation after being overloaded. The test method can be used to send a small value between the throughput of 110% and the line speed to the router port. After 60 seconds, the time interval between the speed drop to 50% and the last packet loss is reached. This test is meaningless if the router has the wire speed capability.

(6) system reset: The interval between the software reset or power-off restart of the test router and normal operation. Normal operation indicates that data can be forwarded by throughput. The following factors should be taken into account when testing the indicators specified in RFC2544.

Frame format: it is recommended to test according to the frame format specified by RFC2544. Frame Length: Increases sequentially from the minimum frame to the MTU. For example, 64,128,256,512,102 4, 1280,151 8 bytes are used on the Ethernet, And the received frame is authenticated: exclude received non-test frames, such as control frames and route update frames. Broadcast frames: Verify the impact of broadcast frames on vro performance, after the above tests, 1% broadcast frames are included in the test frames and then tested. Management frames: Verify the impact of management frames on vro performance, after the above tests, a management frame is included in the test frame and then tested. route update: The Impact of route update on the performance of the next hop port; filter: we recommend that you set 25 filter conditions to test the impact on the performance of the vro. Protocol address: test the performance impact of the vro when it receives a random address in 256 networks; two-way traffic: test the impact of two-way data transmission and receiving on the performance of the router port. multi-port test: consider the impact of full traffic distribution or non-full connection distribution on the performance. multi-protocol test: consider the impact of vro processing multiple protocols at the same time; hybrid package length: in addition to the recommended incremental package length, check the hybrid package Length Because RFC2544 does not specify the proportion of the length of each package in the length of the hybrid package except for the length of all test packages. We recommend that you test the packet length distribution in the actual network. For example, if there is no special application requirement, the Ethernet interface can use 60-byte packet 50%, 128-byte packet 10%, and 256-byte packet 15%, 512 bytes package 10%, 1500 bytes package 15%. In addition to the above RFC2544 recommended test items, we also recommend that you test the following content.

① Route fluctuation: The Impact of Route fluctuation on the router forwarding capability. The number of Route updates per second depends on the network condition. BGP can be used for route update protocols.

② Route table capacity: test the route table size. Backbone Network routers generally run BGP, and the route table contains a global route. Generally, more than 0.1 million routes are required. We recommend that you use BGP input to export route count for testing.

③ Clock Synchronization: test the clock accuracy and synchronization capability on a router with corresponding ports, such as the POS port.

④ Protocol convergence time: the time when the route change notification is sent to the entire network. Although this indicator is related to the performance of the router to test the performance of a single machine, it can only be tested on the network, and the configuration changes. After the network configuration is complete, you can check this indicator to measure the network performance. The test time should be determined based on the specific project and test objectives. Generally, the test time should be between 60 seconds and 300 seconds. In addition, you can set options based on user requirements and test objectives. Generally, the Remote Test method can be used for router testing.

(3) Consistency Test

The router test consistency test usually uses the black box method. The IUT device is called the Black Box ". The test system controls the PCO of the observation point and interfaces of the tested device. Different test events are controlled and observed through different PCO, and whether the response complies with the specifications, that is, the timing relationship and data matching restrictions, the test results can be divided into pass, fail, and no results. Vro testing is a complex network interconnection device that requires multiple protocols on each communication layer. For example, the physical layer and link layer protocols of corresponding interfaces, Internet layer protocols such as IP/ICMP, transport layer protocols such as TCP/UDP, application layer protocols such as Telnet/SNMP, and routes such as RIP/OSPF/BGP protocol.

The protocol consistency test should contain all the protocols implemented by the router. Due to the complexity of the Test content, you can choose an important protocol and content to test. Because the routers on the backbone network may affect global routes, we should pay special attention to the test of route protocol consistency, such as OSPF and BGP. Since only limited test cases can be selected for consistency testing, it generally cannot cover all the content of the Protocol. Therefore, even if the device passes the test, it cannot ensure that the device fully implements all the content of the Protocol. Therefore, the best way is to pilot the operation in the real environment. Generally, the router consistency test adopts the distributed or remote test method.

(4) interoperability test

Because communication protocols and routing protocols are complex and have many options, the test of the same Protocol cannot ensure interoperability. In addition, due to limited consistency testing capabilities, even protocol consistency testing may not guarantee full implementation of the Protocol. Therefore, it is necessary to perform device interoperability testing. In fact, interoperability testing replaces the instruments used in the consistency testing with the devices that need to interwork with each other, and selects some important and typical interconnection mode configurations, check whether the two devices work as expected.

(5) stability and reliability testing

Because most router tests require 24 hours a day and work 7 consecutive days a week, the stability and reliability of the backbone router as the Internet core equipment are particularly important. Therefore, you need to understand the stability and reliability of the dew collector. It is difficult to test the stability and reliability of routers. Generally, the following two methods can be used: (1) the manufacturer calculates the system reliability through the reliability of key components and the degree of backup; (2) the user or manufacturer collects statistics on product stability and reliability based on failure rates of a large number of identical products. Of course, you can also ensure the reliability and stability of the router to a certain extent by demanding the test run results within a certain period of time.

(6) Network Management Test

Network Management tests generally test the management capability of network management software on networks and devices on networks. As a vro is the core device of the IP network, you must test the support of the vro for network management. If the vro comes with network management software, you can use the attached network management software to check the configuration management, security management, performance management, accounting management, fault management, topology management, and view management functions implemented by the network management software. If the vro does not contain network management software, the consistency of the SNMP protocol and the degree to which the MIB is implemented by the vro should be tested. Because the vro needs to implement a large number of MIB, each MIB contains a large amount of content, it is difficult to fully test the MIB. Generally, you can test the implementation of the mib on the vro by testing important MIB items.